Communication systems often transmit communication signals between stations or remote locations. The different locations may be remote locations or as close as a foot apart in a backplane environment. The communications signals are often transmitted over metallic conductors, hereinafter lines, which are often located in close proximity. The proximity of the lines are particularly close when a high density connector is utilized to connect multiple lines to the communication system.
Crosstalk coupling between lines occurs when an electromagnetic field generated by a signal in one line couples into and becomes part of a signal in another line. Crosstalk is generally understood to be unwanted and undesirable. In some systems the primary source of contact is the mechanical assembly consisting of the PCB/connector/cable launch or vice versa (cable to PCB) and can be considered as the end point. Alternatively, crosstalk couples between lines based on the parameters of the signal on the line and the proximity of the lines. Either or both sources can dominate depending on the system. As a result, signals in proximately located lines will contain unwanted crosstalk coupling from other nearby lines.
The invention disclosed herein overcomes the drawbacks of the prior art by providing a method and apparatus for crosstalk cancellation.